Generally, a Ubiquitous Sensor Network (USN) means a network system which processes and manages information by constituting a wireless sensor network using a plurality of sensor nodes each including a sensor capable of detecting information about recognition of objects or information about peripheral environments, and by connecting information, input through various sensors, to the outside in real time over a network. The USN ultimately provides all objects with computing and communication functions, thereby aiming at realizing an environment in which communication can be performed regardless of the type of network, device, or service, anytime and anywhere.
The general construction of the USN includes a plurality of sensor nodes, each of which is configured to include a communication module and a sensor for detecting information about recognition of objects or information about peripheral environments, sensor fields, each of which is provided with a set of sensor nodes, a sink node, which is configured to receive information collected from the sensor fields, and a gateway, which is configured to route information received from the sink node and then transmit the routed information to a management server over a broadband network. In this configuration, the sink node can be connected to the gateway using an existing infrastructure such as satellite communication, a wireless Local Area Network (LAN), Bluetooth, and the wired Internet. The USN can be used to detect the fact that a disaster has occurred and manage the disaster when a disaster, such as a fire, a flood, or an earthquake, occurs.
However, in the case in which the functions of a wireless sensor network are added or maintained, trouble must be taken to collect the plurality of sensor nodes in order to update firmware installed in the respective sensor nodes, which are distributedly installed at respective sites. Further, after the sensor nodes, which are actually scattered in a wide area, are collected and then updated, the sensor nodes must be installed in their original locations again, so that a problem occurs in that large amounts of time and money for collecting and reinstalling the sensor nodes are required.